Cardiovascular events are the number one leading cause of death in patients with end-stage renal disease (ESRD.) Increased sympathetic nerve (SNS) activity may contribute to raising blood pressure (BP) and cardiovascular events in these patients. The hypothesis tested in this study is that muscle deconditioning increases SNS activity in ESRD, and that aerobic exercise may improve SNS activity and BP in these patients. ESRD patients will be tested for abnormal skeletal muscle reflex activation to determine if this abnormality contributes to sympathetic hyperactivity. Specifically, blunting of metaboreceptor activation and augmentation of mechanoreceptor activation is expected in ESRD patients. If there is altered muscle reflex activation in patients with ESRD, exercise training may restore metaboreceptor sensitivity and decrease mechanoreceptor sensitivity in these patients. A short-term thrice weekly exercise regimen during hemodialysis will be instituted and the effects of this intervention on sympathetic hyperactivity and blood pressure will be measured. [unreadable] [unreadable] [unreadable]